TORONTO -- Two men accused of plotting to derail a train travelling between Canada and the U.S. believed Islam was a "powerful weapon" which had the potential to wreak havoc on the world, their trial heard Thursday.

Raed Jaser and Chiheb Esseghaier, however, were also aware of the need to blend into Canadian society, a jury heard, in order to carry out their alleged plans without coming under suspicion.

Jaser and Esseghaier both face multiple terror-related charges in the alleged plot to attack a passenger train between New York and Toronto. Not guilty pleas have been entered for both men.

Their alleged plans and their radical Islamic beliefs are detailed in numerous conversations they had with an undercover FBI officer, who said he gained their trust.

Secret audio recordings of those conversations are being played at trial while the officer testifies.

"Islam is a monster, is a beast," Jaser is heard saying on one intercepted conversation. "Islam is a very powerful weapon, OK, and if it's in the right hands...then you can bulldoze the whole world."

The conversation between Jaser, Esseghaier and the undercover agent took place at a Toronto park in September 2012 as children played nearby, the court heard.

The discussion on religious beliefs came just a day after the full extent of the alleged train plot, as well as a "long-term" plan to use a sniper to attack leaders in Canadian society, had been revealed to the officer by the two men.

As the trio sat under a gazebo sipping tea and grazing on Timbits, Jaser talked of his desire to have Shariah or Islamic law imposed in Canada to stop the "wickedness" that exists in Western society.

"Islam is here to conquer," he is heard saying. "There is no live and let live in Islam."

Despite his strong views, Jaser also repeatedly emphasized how important it was for the trio to "stay invisible" and "blend, blend, blend" into North American society.

"We are in a war," he is heard saying. "The war is deception ok, so you need to play certain parts."

Jaser goes on to explain that he is one person around his wife, another around his co-workers, and a different one in front of Esseghaier and the undercover agent.

"But inside, inside I'm very comfortable," he is heard saying. "My heart is very happy."

Two short video clips of the men while they were in the park were played in court and showed Jaser dressed in a long white robe and a red chequered Islamic scarf on his head. Esseghaier is seen wearing a camouflage jacket and an orange baseball cap.

When talk switches to the specifics of the alleged plot to derail the train, the trio discuss Esseghaier taking a reconnaissance trip on a train between Montreal, where he lives, and Toronto, where Jaser is based.

Of particular importance was a look at the first-class carriage, the trial heard.

"When the loss is at the upper class...they will go crazy," Jaser is heard saying. "It will hurt them a lot."

The trial has heard the alleged plot would see two men drill a hole in a railway bridge under cover of darkness to derail the train.

A video would then be posted online to proclaim the incident as retaliation for Canadian and American military action in Muslim countries, court has heard.

The undercover FBI agent, who was posing as a wealthy American businessman with radical views, was to help Jaser and Esseghaier procure equipment to sabotage the railway bridge, and assist them with uploading the video to the Internet, court has heard.

Jaser and Esseghaier were arrested in April 2013.